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In this study, 6:2 and 8:2 polyfluoroalkyl phosphate diester (diPAP) were individually investigated in lysimeters under near-natural conditions. Leachate was sampled for 2 years, as was the soil after the experiment. In the leachate of the diPAP spiked soils, perfluorocarboxylic acids (PFCAs) of different chain lengths were detected [23.2% (6:2 diPAP variant) and 20.8% (8:2 diPAP variant) of the initially applied molar amount]. After 2 years, the soils still contained 36-37% 6:2 diPAP and 41-45% 8:2 diPAP, respectively, in addition to smaller amounts of PFCAs (1.5 and 10.6%, respectively). Amounts of PFCAs found in the grass were low (

In the environmental risk assessment of substances, toxicity to aquatic plants is evaluated using, among other methods, the 7 dayLemna sp. growth inhibition test following the OECD TG 221. So far, the test is not applicable for short-term screening of toxicity, nor does it allow evaluation of toxic modes of action (MoA). The latter is also complicated by the lack of knowledge of gene functions in the test species. Using ecotoxicogenomics, we developed a time-shortened 3 day assay inLemna minor which allows discrimination of ecotoxic MoA. By examining the changes in gene expression induced by low effect concentrations of the pharmaceutical atorvastatin and the herbicide bentazon at the transcriptome and proteome levels, we were able to identify candidate biomarkers for the respective MoA. We developed a homology-based functional annotation pipeline for the reference genome ofL. minor, which allowed overrepresentation analysis of the gene ontologies affected by both test compounds. Genes affected by atorvastatin mainly influenced lipid synthesis and metabolism, whereas the bentazon-responsive genes were mainly involved in light response. Our approach is therefore less time-consuming but sensitive and allows assessment of MoA in L. minor. Using this shortened assay, investigation of expression changes of the identified candidate biomarkers may allow the development of MoA-specific screening approaches in the future.

Vor dem Hintergrund des Schadensfalls mit per- und polyfluorierten Alkylsubstanzen (PFAS) in Baden-Württemberg, bei dem landwirtschaftliche Nutzflächen durch PFAS-haltige Papierschlämme kontaminiert wurden, erfolgten im Rahmen des BWPLUS-Verbundvorhabens PROSPeCT Untersuchungen zum Sorptions- und Transportverhalten von PFAS im Boden sowie zum Transfer in die einzelnen Kompartimente der Maispflanze. Unter Labor- und Feldbedingungen wurde das Abbauverhalten der polyfluorierten Alkylphosphatdiester 6:2 diPAP und 8:2 diPAP in perfluorierte Carbonsäuren (PFCAs) im Pfad Boden-Sickerwasser sowie Boden-Pflanze erforscht und wichtige Einflussfaktoren bestimmt.

Per- and polyfluoroalkyl substances (PFAS) are organic contaminants which are ubiquitous in the environment and anthropogenically manufactured. The presence of PFAS in the environment is connected to their production, use and disposal, i.e. the whole life cycle. Contact with organisms can have adverse effects such as toxicity, bioaccumulation and carcinogenicity depending on the specific compound. There are several thousands of different PFAS with different structures and properties, which differ in their environmental behaviour as well. One example is biotransformation, which is not observed for all PFAS, such as the persistent group of perfluoroalkyl acids (PFAAs). Other PFAS, such as polyfluoroalkyl phosphate diesters (diPAP), act as precursors which are transformed into the stable PFAAs. When released to the environment, it is important to have information about the relevant processes such as adsorption, transformation and formation of non-extractable residues (NER).In this study, leaching simulations were performed using a multi-objective parameter optimization algorithm (caRamel) in R connected to the MACRO 5.2 model. The simulation is based on a lysimeter study with two transformable precursors (6:2 diPAP and 8:2 diPAP) under near-natural conditions and a duration of two years. Objective functions of masses in the percolation water, in the soil and in the grass, planted on the lysimeter, were optimized simultaneously for diPAPs and related persistent PFAA metabolites. The model setup was based on past leaching simulations of soil columns with similar soils, the same substances and the same study duration. A comparison of lysimeter and soil column simulations indicates temperature-affected transformation kinetics, which could be related to the microbial activity. In further studies, the influence of environmental parameters on the transformation of diPAPs should be focussed to evaluate the results of this study.

In this study, we compare analytical methods for PFAS determination–target analysis, non-target screening (NTS), direct total oxidizable precursor assay (dTOPA) and extractable organically bound fluorine (EOF). Therefore, suspended particulate matter (SPM) samples from German rivers at different locations in time series from 2005 to 2020 were analyzed to investigate temporal and spatially resolved trends. In this study 3 PFAS mass balances approaches were utilized: (i) PFAA target vs. PFAS dTOPA, (ii) PFAS target vs. EOF and (iii) PFAS target vs. PFAS dTOPA vs. organofluorines NTS vs. EOF. Mass balance approach (i) revealed high proportions of precursor substances in SPM samples. For the time resolved analysis an increase from 94% (2005) to 97% in 2019 was observable. Also for the spatial resolved analysis precursor proportions were high with >84% at all sampling sites. Mass balance approach (ii) showed that the unidentified EOF (uEOF) fraction increased over time from 82% (2005) to 99% (2019). Furthermore, along the river courses the uEOF increased. In the combined mass balance approach (iii) using 4 different analytical approaches EOF fractions were further unraveled. The EOF pattern was fully explainable at the sampling sites at Saar and Elbe rivers. For the time resolved analysis, an increased proportion of the EOF was now explainable. However, still 27% of the EOF for the time resolved analysis and 25% of the EOF for the spatial resolved analysis remained unknown. Therefore, in a complementary approach, both the EOF and dTOPA reveal unknown gaps in the PFAS mass balance and are valuable contributions to PFAS risk assessment. Further research is needed to identify organofluorines summarized in the EOF parameter.

Robusta and Arabica green beans were supplemented with carbon 14-glyphosate labelled on each carbon position alternatively prior to roasting, up to 220 °C for Robusta and 200 °C for Arabica (2, 5 and 10 min). The results of the study point a significant decomposition of glyphosate that happens during roasting, from at least 42 % to > 74 % depending on roasting conditions (time, temperature) and coffee variety. The data obtained with 14C-labelled glyphosate materials suggest that the carboxymethyl branch of the compound degrades more effectively than the phosphonomethyl moiety. The degradation of glyphosate does not lead to the formation of aminomethylphosphonic acid (AMPA). The results of the study indicate that carbon dioxide, methylamine and dimethylamine are major degradation products of glyphosate formed along coffee roasting, likely released with the roasting gas. Ultimately, the results of the study show that levels of glyphosate in green beans do not mirror those in coffee beverages.

A large number of apex predator samples are available in European research collections, environmental specimen banks and natural history museums that could be used in chemical monitoring and regulation. Apex predators bioaccumulate pollutants and integrate contaminant exposure over large spatial and temporal scales, thus providing key information for risk assessments. Still, present assessment practices under the different European chemical legislations hardly use existing chemical monitoring data from top predators. Reasons include the lack of user-specific guidance and the fragmentation of data across time and space. The European LIFE APEX project used existing sample collections and applied state-of-the-art target and non-target screening methods, resulting in the detection of > 4,560 pollutants including legacy compounds. We recommend establishing infrastructures that include apex predators as an early warning system in Europe. Chemical data of apex species from freshwater, marine and terrestrial compartments should become an essential component in future chemical assessment and management across regulations, with the purpose to (1) validate registration data with ‘real world’ measurements and evaluate the predictability of current models; (2) identify and prioritise hazardous chemicals for further assessment; (3) use data on food web magnification as one line of evidence to assess biomagnification; (4) determine the presence of (bio)transformations products and typical chemical mixtures, and (5) evaluate the effectiveness of risk management measures by trend analysis. We highlight the achievements of LIFE APEX with regard to novel trend and mixture analysis tools and prioritisation schemes. The proposed advancements complement current premarketing regulatory assessments and will allow the detection of contaminants of emerging concern at an early stage, trigger risk management measures and evaluations of their effects with the ultimate goal to protect humans and the environment. This is the second policy brief of the LIFE APEX project.

Monitoring data from apex predators were key drivers in the development of early chemicals legislations due to the population declines of many species during the twentieth century, which was linked to certain persistent organic pollutants (POPs). Besides triggering the development of global treaties (e.g. the Stockholm Convention), chemical monitoring data from apex predators have been particularly important for identifying compounds with bioaccumulative properties under field conditions. Many apex predators are protected species and only a few environmental specimen banks (ESBs) regularly collect samples as many ESBs were established during the 1980–1990s when apex predators were scarce. Today, many POPs have been banned, which contributed to the recovery of many apex predator populations. As a consequence, apex predator samples are now available in research collections (RCs) and natural history museums (NHMs). These samples can be used for routine analysis as well as for screening studies using novel analytical techniques and advanced data treatment workflows, such as suspect and non-target screening. The LIFE APEX project has demonstrated how these samples can be used in a cost-efficient way to generate data on legacy compounds and contaminants of emerging concern. Furthermore, it has described quality assurance/control measures to ensure high quality and comparable data, with a view to uses in chemicals risk assessment and management. To increase the visibility of available sample collections and monitoring data from apex predators we developed accessible online database systems. Additionally, the acquired high-resolution mass spectrometric data were stored in a digital sample freezing platform that allows retrospective suspect screening in previously analysed samples for substances that may be of concern/under assessment in the future. These databases provide open access to a wide range of chemical data, for use by regulators, researchers, industry and the general public, and contribute to a stronger link between science and policy.

Fluorotelomer precursors in soil constitute a reservoir for perfluoroalkyl acids (PFAAs) in the environment. In the present study, precursor degradation and transfer rates of seven fluorotelomer precursors and F-53B (chlorinated polyfluoroalkyl ether sulfonates) were investigated in pot experiments with maize plants (

Per- and polyfluoroalkyl substances (PFAS) are environmentally ubiquitous, anthropogenic substances with adverse effects on organisms, which shows the need to study their environmental fate and leaching behavior. In the present soil columns study, the leaching behavior and fate of nontransformable and transformable (precursors) were investigated. Ten nontransformable PFAS in two different soils, two precursors and two field soils, which were already contaminated with a mixture of PFAS, and two uncontaminated controls, were set up for a time span of 2 years. At the end of the study, the molecular balance could not be closed for nontransformable PFAS. This effect was positively correlated to the fluorinated carbon chain length. The precursors, which were both polyfluoroalkyl phosphate diesters (diPAP), had different transformation products and transformation rates, with a higher rate for 6:2 diPAP than 8:2 diPAP. After 2 years, amounts of diPAP were still found in the soil with no significant vertical movement, showing high adsorption to soils. Transformation products were estimated to be simultaneously formed. They were predominantly found in the percolation water; the amounts left in soil were negligible. Up to half of the initial precursor amounts could not be balanced and were considered missing amounts. The results of contaminated field soil experiments showed the challenge to estimate PFAS leaching without knowing all occurring precursors and complex transformation dynamics. For this purpose, it was shown that a broad examination of contaminated soil with different analytical methods can help with qualitative estimations of leaching risks. For a better quantitative estimation, analytical determination of more PFAS and a quantification of the missing amounts are needed. Environ Toxicol Chem 2022;41:2065-2077. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

A feeding study was performed to examine the bioaccumulation of per- and polyfluoroalkyl substances (PFAS) in laying hens' tissues and plasma and feed-to-egg transfer rates and half-lives. A 25 day exposure was followed by a 42 day depuration period. A target analysis revealed substantial amounts of the precursors N-methyl and N-ethyl perfluorooctane sulfonamidoacetic acid (Me- and EtFOSAA), perfluorooctane sulfonamidoacetic acid (FOSAA), and perfluorooctane sulfonamide (FOSA). In tissues and eggs, the highest bioaccumulation was found for PFHxS, PFHpS, PFOS, and PFOA. Low levels of PFHxS (all samples), PFOS, and FOSAA (in yolk) were measurable even after the depuration period. The egg elimination half-lives of PFOS and aforementioned precursors were estimated to be 4.3 days, while the transfer rates of PFOS and all precursors taken together were 0.99. The transfer rate of PFOA was around 0.49. PFHxS and PFHpS showed apparent transfer rates of >100%, which is hypothesized to indicate the presence of precursors.

Suspended particulate matter (SPM) from 13 riverine sampling sites of the German Environmental Specimen Bank collected between 2005 and 2019 was retrospectively investigated for per- and polyfluoroalkyl substances (PFAS). The samples were analyzed both by target analysis for 41 PFAS and by a modified total oxidizable precursor (dTOP) assay to capture also unknown precursors. Temporal trends and spatial differences were investigated by generalized linear modeling (GLM). Time trend analysis across all rivers showed decreasing trends for ∑PFCA and ∑PFSA concentrations in SPM. Trends based on target analysis (∑PFCAtarget: -10.0%, ∑PFSAtarget: -8.2%) were more pronounced than in the dTOP analysis (∑PFCAdTOP: -4.2%; ∑PFSAdTOP: -5.3%), suggesting that conventional target analysis overestimated actual decreases as precursors are not considered. ∑PFAS concentrations determined by dTOP assay were 1.3-145 times higher as compared to target analysis, indicating substantial amounts of unknown precursors in the samples. The ∑PFASdTOP/∑PFAStarget ratio increased at all sites between 2005 and 2019. Contamination was highest in SPM from the Elbe tributary Mulde downstream of a large industrial park. The results underscore the need to go beyond conventional target analysis and include precursors when assessing PFAS contamination in the environment. The dTOP assay is a suitable tool for this purpose.

The study highlights the potential of Environmental Specimen Banks (ESBs) for implementing the Zero Pollution Ambition and the Biodiversity Strategy of the European Green Deal. By drawing on recent monitoring studies of European ESBs, we illustrate the role ESBs already play in assessing the state of ecosystems in Europe and how they help to make developments over time visible. The studies reveal the ubiquitous presence of per- and polyfluoroalkyl substances, halogenated flame retardants, chlorinated paraffins, plasticizers, cyclic volatile methyl siloxanes, UV-filters, pharmaceuticals, and microplastics in the European environment. Temporal trends demonstrate the effectiveness of European regulations on perfluorooctane sulfonic acid, pentabrominated diphenylethers and diethylhexyl phthalate, but also point to the rise of substitutes such as non-phthalate plasticizers and short-chain perfluoroalkyl substances. Other studies are wake-up calls indicating the emergence of currently unregulated compounds such as long-chain chlorinated paraffins. Ecological studies show temporal trends in biometric parameters and stable isotope signatures that suggest long-term changes in environmental conditions. Studies on biodiversity of ecosystems using environmental DNA are still in their beginnings, but here too there is evidence of shifts in community composition that can be linked to changing environmental conditions. This review demonstrates the value of ESBs (a) for describing the status of the environment, (b) for monitoring temporal changes in environmental pollution and the ecologic condition of ecosystems and thereby (c) for supporting regulators in prioritizing their actions towards the objectives of the Green Deal.

Using monitoring data from apex predators for chemicals risk assessment can provide important information on bioaccumulating as well as biomagnifying chemicals in food webs. A survey among European institutions involved in chemical risk assessment on their experiences with apex predator data in chemical risk assessment revealed great interest in using such data. However, the respondents indicated that constraints were related to expected high costs, lack of standardisation and harmonised quality criteria for exposure assessment, data access, and regulatory acceptance/application. During the Life APEX project, we demonstrated that European sample collections (i.e. environmental specimen banks (ESBs), research collection (RCs), natural history museums (NHMs)) archive a large variety of biological samples that can be readily used for chemical analysis once appropriate quality assurance/control (QA/QC) measures have been developed and implemented. We therefore issued a second survey on sampling, processing and archiving procedures in European sample collections to derive key quality QA/QC criteria for chemical analysis. The survey revealed great differences in QA/QC measures between ESBs, NHMs and RCs. Whereas basic information such as sampling location, date and biometric data were mostly available across institutions, protocols to accompany the sampling strategy with respect to chemical analysis were only available for ESBs. For RCs, the applied QA/QC measures vary with the respective research question, whereas NHMs are generally less aware of e.g. chemical cross-contamination issues. Based on the survey we derived key indicators for assessing the quality of biota samples that can be easily implemented in online databases. Furthermore, we provide a QA/QC workflow not only for sampling and processing but also for the chemical analysis of biota samples. We focussed on comprehensive analytical techniques such as non-target screening and provided insights into subsequent storage of high-resolution chromatograms in online databases (i.e. digital sample freezing platform) to ultimately support chemicals risk assessment.

Active substances of pesticides, biocides or pharmaceuticals can induce adverse side effects in the aquatic ecosystem, necessitating environmental hazard and risk assessment prior to substance registration. The freshwater crustacean Daphnia magna is a model organism for acute and chronic toxicity assessment representing aquatic invertebrates. However, standardized tests involving daphnia are restricted to the endpoints immobility and reproduction and thus provide only limited insights into the underlying modes-of-action. Here, we applied transcriptome profiling to a modified D. magna Acute Immobilization test to analyze and compare gene expression profiles induced by the GABA-gated chloride channel blocker fipronil and the nicotinic acetylcholine receptor (nAChR) agonist imidacloprid. Daphnids were expose to two low effect concentrations of each substance followed by RNA sequencing and functional classification of affected gene ontologies and pathways. For both insecticides, we observed a concentration-dependent increase in the number of differentially expressed genes, whose expression changes were highly significantly positively correlated when comparing both test concentrations. These gene expression fingerprints showed virtually no overlap between the test substances and they related well to previous data of diazepam and carbaryl, two substances targeting similar molecular key events. While, based on our results, fipronil predominantly interfered with molecular functions involved in ATPase-coupled transmembrane transport and transcription regulation, imidacloprid primarily affected oxidase and oxidoreductase activity. These findings provide evidence that systems biology approaches can be utilized to identify and differentiate modes-of-action of chemical stressors in D. magna as an invertebrate aquatic non-target organism. The mechanistic knowledge extracted from such data will in future contribute to the development of Adverse Outcome Pathways (AOPs) for read-across and prediction of population effects.

Analyzing the fate of substances in complex matrices, such as processed food, is a major challenge in modern analytical chemistry. However, current regulatory procedures for pesticides only include high temperature hydrolysis of the active substance in water (OECD 507) to simulate food processing. This study shows that heating radiolabeled [imidazolyl-2

Per- and polyfluoroalkyl substances (PFASs) are fluorinated anthropogenic compounds of which numerous have a high thermal stability, high surface tension, water and oil repellence. PFASs are used e.g. as surfactants, in agrochemical products and in fire extinguishing foams. Due to negative effects to the environment and human health some compounds are already declared as Persistent Organic Pollutants (POPs) or Substances of Very High Concern (SVHC). The behaviour of PFASs in environmental matrices can differ dependent on the molecular structure and environmental conditions. Sorption, for example, depends on soil characteristics, compound properties such as the carbon chain length and the functional group. When PFASs are found in soils, the knowledge of factors affecting the leaching behaviour in soil can be helpful to assess plant availability and risk of groundwater contamination.In some contamination cases, e.g. Rastatt/Baden-Baden, Germany, PFASs precursors such as polyfluoroalkyl phosphate diesters (diPAPs) are present in soil and are transformed into PFAAs (perfluoroalkyl acids), a sub-group of PFASs, which are stable in the environment. To study the behaviour of diPAPs in soil, 8:2 diPAP and 6:2 diPAP were applied to 50 cm soil-filled columns with a concentration of 1 mg per kg soil. For two years, the columns are watered on 3-5 days per week with an average weekly natural rainfall of Baden-Württemberg. The leaching water is collected and analysed every two weeks. After the first year, there was no detection of precursors in the leaching water. The main products were, in accordance with literature, PFPeA (Perfluoropentanoic acid) and PFHxA (Perfluorohexanoic acid) for the precursor 6:2 diPAP and PFHpA (Perfluoroheptanoic acid) and PFOA (Perfluorooctanoic acid) for the precursor 8:2 diPAP. The breakthrough peak of PFPeA (864 µg/l) and PFHxA (487 µg/l) was found in week nine after the start of the experiment, the major peak of PFHpA (124 µg/l) in week 15 and the peak of PFOA (303 µg/l) in week 25. Even though the major breakthrough of PFAAs was over after the first year, all of them are still found in leaching water in relatively constant concentrations: ~40 µg PFPeA/l, ~20 µg PFHxA/l (6:2 diPAP) and ~5 µg PFHpA/l, ~50 µg PFOA/l (8:2 diPAP). Thus, as a preliminary result after the first year, there is a higher mass of PFPeA and PFHxA in the leachate compared to PFHpA and PFOA, which can be led back to higher transformation rates of 6:2 diPAP than 8:2 diPAP.After two years, the soil columns will be cut horizontally in sections, and the soil will be analysed for precursors and PFAAs in order to calculate a mass balance. This will provide more insight into the transformation and mobilisation behaviour of investigated diPAPs and PFAAs.

The group of per- and polyfluoroalkyl substances (PFAS) comprises thousands of chemicals, which are used in various industrial applications and consumer products. In this study, a feeding experiment with laying hens and feed grown on a contamination site was conducted, and PFAS were analyzed in the feed and eggs to assess the transfer of PFAS into eggs. A targeted analysis of perfluoroalkyl acids (PFAAs) and different sulfonamides was performed. Additionally, the total oxidizable precursor (TOP) assay was modified by fully oxidizing small amounts of the samples instead of oxidizing their extracts in order to overcome potential losses during extraction. Targeted analysis showed the presence of known PFAAs and four sulfonamides in the feed and egg yolk samples. In the plant-based feed, short-chain PFAAs, methyl and ethyl perfluorooctane sulfonamidoacetic acid (Me- and EtFOSAA), and perfluorooctane sulfonic acid (PFOS) were the most abundant PFAS. In the eggs, PFOS, FOSAA, and its alkylated homologues showed the highest concentrations. The TOP assay revealed the presence of substantial amounts of precursors with different chain lengths from C4 to C8. The highest relative increase of PFOA after oxidation was observed in egg yolk from the end of the exposure period (828%). The results of this study demonstrate the transfer of PFAAs and their precursors into hens' eggs and emphasize the contribution of (known and unidentified) precursors to the overall PFAS burden in edible products. The modified TOP assay approach was shown to be a powerful tool to better assess the total burden of samples with PFAS.

The findings of per- and polyfluoroalkyl substances (PFAS) in humans and the environment all over the world have raised concerns and public awareness for this group of man-made chemicals. In the last three decades, this led to different regulatory restrictions for specific PFAS as well as shifts in the production and usage of these substances. In this study, we analyzed the PFAS levels of 100 human blood plasma samples collected from 2009 to 2019 for the German Environmental Specimen Bank (ESB) to further elucidate the time course of exposure towards this substance group as shown by Schröter-Kermani et al., (2013) with samples from 1982 to 2010. A spectrum of 37 PFAS, including perfluorocarboxylic (PFCA) and -sulfonic acids (PFSA) as well as potential precursors and substitutes like ADONA, GenX or F-53B was analyzed by UHPLC coupled with high-resolution mass spectrometry. Validation was successful for 33 of the substances. The two legacy substances perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were detected in every sample of the 2009-2019 dataset and showed the highest concentrations with ranges of 0.27-14.0 ng/mL and 1.21-14.1 ng/mL, respectively. A significant portion of total PFOS analytes was present as branched isomers (mean: 34 ± 7%). High detection frequencies of 95% and 82% were also found for perfluorohexane sulfonic acid (PFHxS) and perfluorononanoic acid (PFNA), respectively, but in lower concentrations (PFHxS

Per- and polyfluoroalkyl substances (PFAS) in the environment mostly originate from emissions of previously unregulated PFAS. However, there are also many documented incidents of accidental releases. To track such releases, it is essential to distinguish between typical background contamination and legally relevant incidents. This requires a comprehensive overview of all PFAS present in the environment, which is currently only possible to a limited extent due to the large variety of individual compounds. In the present study, a multimethod for capturing 41 PFAS including perfluoroalkyl acid (PFAA) precursors is introduced. The applicability of the method was tested on terrestrial, freshwater and marine samples from the German Environmental Specimen Bank (ESB), thereby providing a rough overview of PFAS contamination in German environment. Special focus was put on soil samples from ESB sites across Germany in comparison to soil samples from a polluted site in south-west Germany. The method was successfully applied to environmental samples. In total, 31 PFAS were detected, among them PFAA precursors and fluorinated ethers. Substance patterns differed between sites and matrices. In ESB soil samples from 2014 (n = 11), the sum of all captured PFAS ranged between 0.75 and 19.5 μg kg−1 dry weight (dw), while concentrations between 416 μg kg−1 and 3530 μg kg−1 were detected in samples from the incident site (n = 10). In other matrices, total PFAS concentrations were magnitudes lower. Highest concentrations were observed for PFOS in bream livers from the Saale (226 μg kg−1). Given the heterogeneous patterns, it will require further broadly-based monitoring data to allow for a solid estimation of relevant background levels. The data provided here may support the differentiation between background levels and hotspot contaminations.

Zur Untersuchung der Rückstände von Neonicotinoiden und Pyrethroiden in Ackerböden wurden in 2018 von vier Zuckerrübenäckern im Niederrheinischen Tiefland im Mai, Juli und September Bodenproben entnommen und auf Neonicotinoide und Pyrethroide untersucht. Informationen zu den Aufwandmengen der in den letzten vier Jahren eingesetzten Pestizide waren von den Landwirten zur Verfügung gestellt worden. Zusätzlich wurden drei unbehandelte Flächen im Umfeld der Zuckerrübenäcker beprobt und analysiert. Hohe Gehalte wurden für Imidacloprid, Clothianidin und Thiamethoxam gefunden. Imidacloprid war auf allen Flächen, wenn auch teilweise nur in Spuren, nachweisbar und wurden damit auch auf unbehandelten Flächen gefunden. Die untersuchten Äcker waren mit zwei bis sechs verschiedenen Wirkstoffen belastet. Die Bodengehalte zeigten sowohl im saisonalen Verlauf als auch innerhalb einer an mehreren Stellen untersuchten Fläche deutliche Schwankungen, die zumindest teilweise auf die Ausbringung als Saatgutbeize zurückzuführen sind. Generell waren die Gehalte für die in 2018 ausgebrachten Insektizide am höchsten, während die 2015 verwendeten Wirkstoffe nur noch in Spuren nachweisbar waren.

Anticoagulant rodenticides are used worldwide to control commensal rodents for hygienic and public health reasons. As anticoagulants act on all vertebrates, risk is high for unintentional poisoning of terrestrial and aquatic wildlife. Causative associations have been demonstrated for the unintended poisoning of terrestrial nontarget organisms. However, behavior and fate of anticoagulant rodenticides in the aquatic environment have received minimal attention in the past despite considerable acute toxicity of several anticoagulants to aquatic species such as fish. In light of recent regulatory developments in the European Union concerning rodenticides, we critically review available information on the environmental occurrence, fate, and impact of anticoagulant rodenticides in the aquatic environment and identify potential risks and routes of exposure as well as further research needs. Recent findings of anticoagulant rodenticides in raw and treated wastewater, sewage sludge, estuarine sediments, suspended particulate matter, and liver tissue of freshwater fish in the low ng/L and µg/kg range, respectively, demonstrate that the aquatic environment experiences a greater risk of anticoagulant rodenticide exposure than previously thought. While the anticoagulant's mechanism of action from the molecular through cellular levels is well understood, substantial data gaps exist regarding the understanding of exposure pathways and potential adverse effects of chronic exposure with multiple active ingredients. Anticoagulants accumulating in aquatic wildlife are likely to be transferred in the food chain, causing potentially serious consequences for the health of wildlife and humans alike.

Limnetic, marine and soil samples of the German environmental specimen bank (ESB) were analyzed for per- and polyfluoroalkyl substances (PFAS) using target analysis and a modified total oxidizable precursor (TOP) assay (direct TOP assay (dTOP)) that works without prior extraction. Target analysis determined ∑PFAS concentrations in bream livers of 8.7–282 μg kg−1 wet weight (ww) in 2019, with highest contaminations in the Rhine and lower Elbe. In bream fillet, concentrations were lower ( The dTOP assay revealed that considerable amounts of precursors were present at most riverine sampling sites. Particularly high precursor concentrations were observed in samples from the Upper Elbe at the Czech border and the Upper and Middle Rhine. In herring gull eggs and most soil samples, though, concentrations of precursors were low. Time trend analysis showed decreasing trends for most detected PFAS since 2005. In SPM, however, C4-C6 perfluoroalkyl carboxylic acids seem to increase indicating growing use of precursors based on shorter fluorinated chains. The results demonstrate that target analysis detects only a minor fraction of the PFAS burdens in environmental samples. The dTOP assay can support risk assessment and chemical monitoring with more comprehensive exposure data of the actual contamination.

Endocrine disruption (ED) can trigger far-reaching effects on environmental populations, justifying a refusal of market approval for chemicals with ED properties. For the hazard assessment of ED effects on the thyroid system, regulatory decisions mostly rely on amphibian studies. Here, we used transcriptomics and proteomics for identifying molecular signatures of interference with thyroid hormone signaling preceding physiological effects in zebrafish embryos. For this, we analyzed the thyroid hormone 3,3',5-triiodothyronine (T3) and the thyroid peroxidase inhibitor 6-propyl-2-thiouracil (6-PTU) as model substances for increased and repressed thyroid hormone signaling in a modified zebrafish embryo toxicity test. We identified consistent gene expression fingerprints for both modes-of-action (MoA) at sublethal test concentrations. T3 and 6-PTU both significantly target the expression of genes involved in muscle contraction and functioning in an opposing fashion, allowing for a mechanistic refinement of key event relationships in thyroid-related adverse outcome pathways in fish. Furthermore, our fingerprints identify biomarker candidates for thyroid disruption hazard screening approaches. Perspectively, our findings will promote the AOP-based development of in vitro assays for thyroidal ED assessment, which in the long term will contribute to a reduction of regulatory animal tests.

Biodegradable polymers must degrade completely to CO2, H2O, small and non-toxic molecules (e.g. NO3− and NH3/NH4+), and biomass on a similar timescale to classically compostable materials (3–12 months). More importantly, the degradation intermediates - the compounds that form as a polymeric material breaks down in the environment, before being mineralized or bio-assimilated also need to be non-toxic. Here, for the first time, the identity of the degradation intermediates formed from the breakdown of a sprayable, biodegradable poly(ester-urethane-urea) was investigated using a liquid chromatography mass spectrometry (LC-MS) system. This was accomplished by degrading the polymer in abiotic aqueous media for varying lengths of time and in soil media for 57 days, and analyzing the degradation media for polymer degradation intermediates. It was found that during degradation, monomers and short oligomers were formed containing amino, alcohol and carboxylic acid moieties. Interestingly, the most prominent degradation products formed during abiotic degradation (6-hydroxy hexanoic acid, and its oligomers) were not detectable when the polymer was degraded in a soil environment. Gel permeation chromatography confirmed that the polymer's molecular weight was substantially reduced during the degradation studies, but the presence of polymer fragments >1000 Da in the soil indicated that there would be an ongoing release of 6-hydroxy hexanoic acid and its oligomers. Taken together this suggests that those molecules were rapidly bio-assimilated by the soil microbial community.

Over the past decades, thousands of different per- and polyfluoroalkyl substances (PFASs) have been produced and applied in various industrial processes and consumer products. Their structural diversity has reached a level that cannot be covered by classical target screening methods for individual compounds. Large-scale contaminations of soil, however, require the need to adapt new analytical methods that can describe a contamination more comprehensively. While sum parameters such as the total oxidisable precursor (TOP) assay have been developed in the past years, they are not yet applied in the regulatory context of PFASs.In this commentary, we provide an overview on different approaches of the TOP assay as well as its benefits and disadvantages to other sum parameters for PFASs in soil samples. Furthermore, we elaborate its opportunities and its challenges that need to be tackled to implement the TOP assay as a regulatory tool. With several different approaches of the TOP assay being available, a sound and standardised method needs to be agreed upon and more research is necessary to better describe the method. Although the complexity of PFAS contaminations in soil cannot be fully covered by any analytical method alone, the TOP assay can provide valuable data to detect and characterise soil contamination as an inventory for subsequent remediation measures. Therefore, the TOP assay should be implemented as a useful tool both in research and in the regulatory context of PFASs.